It is important for controls in heavy industrial applications to be resistant to unintentional operation. Unintentional operation could be caused from traveling across rough surfaces, from momentary shocks due to impacts on the vehicle chassis or a sudden release of force on a vehicle attachment arm, or from sudden release of the control by the operator.
Conventionally, dampened controls are provided as part of conventional hydraulic control systems. Often, the hydraulic system itself, by the nature of hydraulic fluids, provided some inherent damping.
U.S. Publication No. 2010/0089197 A1 discloses a conventional dampened control, which is operated by moving a spring-supported surface, or treadle, using the operator's foot.
U.S. Pat. No. 6,931,962 B2 discloses another conventional controller. This controller utilizes internal controls and hydraulics to regulate the operator force and limit the speed of depression.
Gradually, hydraulic controls are being replaced with electronic controls. Current methods of dampening electronic pedals use modules which are bolted directly onto the control assembly. These electronic control modules typically utilize stacked Bellville washer disk springs or a fluid filled chamber with a sliding piston.